elf/soinit.c

   1 /* Initializer module for building the ELF shared C library.  This file and
   2    sofini.c do the work normally done by crtbeginS.o and crtendS.o, to wrap
   3    the `.ctors' and `.dtors' sections so the lists are terminated, and
   4    calling those lists of functions.  */
   5
   6 #include <libc-internal.h>
   7 #include <stdlib.h>
   8
   9 #ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  10 # include <gccframe.h>
  11 #endif
  12
  13 static void (*const __CTOR_LIST__[1]) (void)
  14      __attribute__ ((section (".ctors")))
  15      = { (void (*) (void)) -1 };
  16 static void (*const __DTOR_LIST__[1]) (void)
  17      __attribute__ ((section (".dtors")))
  18      = { (void (*) (void)) -1 };
  19
  20 static inline void
  21 run_hooks (void (*const list[]) (void))
  22 {
  23   while (*++list)
  24     (**list) ();
  25 }
  26
  27 #ifdef HAVE_DWARF2_UNWIND_INFO
  28 static char __EH_FRAME_BEGIN__[]
  29      __attribute__ ((section (".eh_frame")))
  30      = { };
  31 # ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  32 extern void __register_frame_info (const void *, struct object *);
  33 extern void __register_frame_info_bases (const void *, struct object *,
  34                                          void *, void *);
  35 extern void __deregister_frame_info (const void *);
  36 extern void __deregister_frame_info_bases (const void *);
  37 # else
  38 extern void __register_frame (const void *);
  39 extern void __deregister_frame (const void *);
  40 # endif
  41 #endif
  42
  43 /* This function will be called from _init in init-first.c.  */
  44 void
  45 __libc_global_ctors (void)
  46 {
  47   /* Call constructor functions.  */
  48   run_hooks (__CTOR_LIST__);
  49
  50 #ifdef HAVE_DWARF2_UNWIND_INFO
  51 # ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  52   {
  53     static struct object ob;
  54 #  if defined CRT_GET_RFIB_TEXT || defined CRT_GET_RFIB_DATA
  55     void *tbase, *dbase;
  56
  57 #   ifdef CRT_GET_RFIB_TEXT
  58     CRT_GET_RFIB_TEXT (tbase);
  59 #   else
  60     tbase = NULL;
  61 #   endif
  62 #   ifdef CRT_GET_RFIB_DATA
  63     CRT_GET_RFIB_DATA (dbase);
  64 #   else
  65     dbase = NULL;
  66 #   endif
  67     __register_frame_info_bases (__EH_FRAME_BEGIN__, &ob, tbase, dbase);
  68 #  else
  69     __register_frame_info (__EH_FRAME_BEGIN__, &ob);
  70 #  endif
  71   }
  72 # else
  73   __register_frame (__EH_FRAME_BEGIN__);
  74 # endif
  75 #endif
  76 }
  77
  78
  79 /* This function becomes the DT_FINI termination function
  80    for the C library.  */
  81 void _fini (void) __attribute__ ((section (".fini"))); /* Just for kicks.  */
  82 void
  83 _fini (void)
  84 {
  85   /* Call destructor functions.  */
  86   run_hooks (__DTOR_LIST__);
  87 #ifdef HAVE_DWARF2_UNWIND_INFO
  88 # ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  89 #  if defined CRT_GET_RFIB_TEXT || defined CRT_GET_RFIB_DATA
  90   __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
  91 #  else
  92   __deregister_frame_info (__EH_FRAME_BEGIN__);
  93 #  endif
  94 # else
  95   __deregister_frame (__EH_FRAME_BEGIN__);
  96 # endif
  97 #endif
  98 }